After nearly 30 years of space travel, NASA's space shuttle Discovery will make its final flight today from Cape Canaveral, Florida.  

Discovery was first launched in 1984, and is one of NASA’s three operational orbiters in the Space Shuttle fleet. It has spent 352 days in orbit and circled the Earth 5,628 times. It has also carried 246 crewmembers, which is more than any other space vehicle has before. After years of International Space Station assembly missions and research missions, Discovery is now the oldest orbiter in service, and will be retiring after today's launch.  

Today's launch, which will be Discovery's 39th journey, was originally set for November 5 of last year, but the launch was delayed due to vital repairs to the external tank's support beams. NASA released the new launch date, February 24, just a few weeks ago.  

"Discovery has been a really remarkable vehicle for us and the program," said Jeff Spaulding, NASA test director. "She still has a few more miles to go before she sleeps, though."

Discovery's final flight will carry a six-member crew for an 11-day mission. The mission objective is to deliver a science rig, a storage module, and spare parts to the international Space Station. In addition, Robonaut 2, a humanoid robot assistant, will be traveling on the Discovery to embark on a permanent stay at the International Space Station.  

The six crew members aboard the Discovery's final flight will be commander and veteran NASA astronaut Steven Lindsey, NASA pilot Eric Boe, and mission specialists Alvin Drew, Michael Barratt, Steven Bowen and Nicole Stott. Originally, astronaut Tim Kopra was supposed to be apart of the six-member crew, but endured a bicycle accident last month that has prevented him from joining the others. Bowen was a last-minute substitute for Kopra. 

At 7:25 a.m. EST (1225 GMT), NASA technicians began filling the Discovery's 15-story, 550,000 gallon tank, which is a three-hour process that consists of pumping liquid hydrogen and liquid oxygen into the tank. The launch is set to take place at 4:50 p.m. EST (2150 GMT). 

"We are really looking forward to a very action-packed, successful mission," said Mike Moses, NASA's shuttle integration manager.

In addition to the Discovery's final launch, space shuttle Endeavour, which is also one of the three operational orbiters at NASA, is set to embark on its final launch as well on April 19.